1、Designation: E2819 11 (Reapproved 2015) An American National StandardStandard Practice forSingle- and Multi-Level Continuous Sampling of a Stream ofProduct by Attributes Indexed by AQL1This standard is issued under the fixed designation E2819; the number immediately following the designation indicat
2、es the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice establishes tables and procedur
3、es forapplying five different types of continuous sampling plans forinspection by attributes using MIL-STD-1235B as a basis forsampling a steady stream of lots indexed by AQL.1.2 This practice provides the sampling plans of MIL-STD-1235B in ASTM format for use by ASTM committees andothers. It recogn
4、izes the continuing usage of MIL-STD-1235Bin industries supported by ASTM. Most of the original text inMIL-STD-1235B is preserved in Sections 610of thispractice.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the us
5、er of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E456 Terminology Relating to Quality and StatisticsE1994 Practice for Use of Process Oriented AOQL andLTPD Samp
6、ling PlansE2234 Practice for Sampling a Stream of Product by Attri-butes Indexed by AQL2.2 Military Standards:3MIL-STD-1235A1 Functional Curves of the ContinuousSampling PlansMIL-STD-1235B Single- and Multi-Level Continuous Sam-pling for Attributes3. Terminology3.1 Definitions:3.1.1 For a more exten
7、sive list of terms in E11 standards seeTerminology E456.3.1.2 acceptance quality limit (AQL), nquality limit that isthe worst tolerable process average when a continuing series oflots is submitted for acceptance sampling. E22343.1.3 average outgoing quality (AOQ), nthe average per-cent defective of
8、outgoing product including all accepted lotsor batches after any defectives found in them are replaced byacceptable units, plus all lots or batches which are not acceptedafter such lots or batches have been effectively 100 % in-spected and all defective units replaced by acceptable units.E19943.1.4
9、average outgoing quality limit (AOQL), nthe maxi-mum AOQ for a given acceptance sampling plan for allpossible incoming percentages defective for the process.E19943.1.5 continuous sampling inspection, na method of sam-pling a stream of product in order of production where thesampling frequency is adj
10、usted based on ongoing inspectionresults.3.1.5.1 DiscussionOnly those units of product found bythe inspector or screening crew to be nonconforming arerejected. The rest of production, uninspected units as well asunits found to be conforming, is allowed to continue down theproduction line as conformi
11、ng material.3.1.6 critical defect, na defect that judgment and experi-ence indicate would result in hazardous or unsafe conditionsfor individuals using, maintaining, or depending upon theproduct, or a defect that judgment and experience indicate islikely to prevent performance of the function of a m
12、ajor enditem. E22343.1.7 critical defective, na unit of product which containsone or more critical defects and may also contain major andminor, or both, defects. E22343.1.8 defect, nany nonconformance of the unit of productwith specified requirements. E22343.1.9 inspection, nthe process of measuring
13、, examining,testing, or otherwise comparing the unit of product with therequirements. E22341This practice is under the jurisdiction of ASTM Committee E11 on Quality andStatistics and is the direct responsibility of Subcommittee E11.30 on StatisticalQuality Control.Current edition approved May 15, 20
14、15. Published June 2015. Originallyapproved in 2011. Last previous edition approved in 2011 as E2819 11. DOI:10.1520/E2819-11R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume informati
15、on, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshoh
16、ocken, PA 19428-2959. United States13.1.10 inspection by attributes, ninspection whereby ei-ther the unit of product is classified simply as defective ornon-defective, or the number of defects in the unit of productis counted, with respect to a given requirement or set ofrequirements. E22343.1.11 ma
17、jor defect, na defect, other than critical, that islikely to result in failure, or to reduce materially the usabilityof the unit of product for its intended purpose. E22343.1.12 major defective, na unit of product which containsone or more major defects, and may also contain minor defectsbut contain
18、s no critical defect. E22343.1.13 minor defect, na defect that is not likely to reducematerially the usability of the unit of product for its intendedpurpose, or is a departure from established standards havinglittle bearing on the effective use or operation of the unit.E22343.1.14 minor defective,
19、na unit of product which containsone or more minor defects but contains no critical or majordefect. E22343.1.15 process average (in inspection), nthe average per-cent defective or average number of defects per hundred units(whichever is applicable) of product submitted by the supplierfor original in
20、spection. E22343.1.16 unit of product, nthat which is inspected in order todetermine its classification as defective or non-defective or tocount the number of defects. It may be a single article, a pair,a set, a length, an area, an operation, a volume, a component ofan end product, or the end produc
21、t itself. E22343.1.16.1 DiscussionThe unit of product may or may notbe the same as the unit of purchase, supply, production, orshipment.3.2 Definitions of Terms Specific to This Standard:3.2.1 checking inspection, nsampling inspection per-formed by the supplier on units of product which have already
22、been 100 % inspected in order to determine the effectiveness ofthe screening crew.3.2.1.1 DiscussionThis inspection is performed at thesampling rate f or more often.3.2.2 clearance number, ni, the number of consecutiveconforming, that is, defect-free, units in 100 % inspectionrequired prior to quali
23、fying for inspection on a sampling basis.3.2.3 conforming unit, na unit that meets the acceptancecriteria established for the characteristic being considered.3.2.4 defects concerned, ndefects being inspected forwhile using the sampling plan.3.2.5 inspection by defect class, nwhen one sampling planis
24、 associated with inspection for several kinds of defectscollectively and each unit of product inspected is inspected foreach of the defects in the class.3.2.6 inspection by individual defect, ninspection whereone sampling plan is associated with inspection for a singledefect, or where a sampling pla
25、n is applied to each of severaldefects independently.3.2.7 moving product, ninspection where product is flow-ing past the inspection station.3.2.7.1 DiscussionIn the typical case the product moveson a conveyor belt or line; however, it may be moved in toteboxes, buggies or other conveyances which ar
26、e operatedmanually or by mobile materials-handling equipment.3.2.8 multi-level, nplan consisting of periods of 100 %inspection and of sampling inspection at various rates whichreflect past inspection results.3.2.9 one hundred percent (100 %) inspection, nthe in-spection of every unit of product for
27、the defects concernedlisted for an inspection station.3.2.9.1 DiscussionThe two terms, screening and 100 %inspection, are used interchangeably in this practice.3.2.10 production interval, na finite period of production,N items in length.3.2.10.1 DiscussionThe production interval is normally ashift;
28、it can be a day if it is reasonably certain that shift changesdo not affect quality of product, but shall not be longer than aday.3.2.11 production interval length, nN, specified numberof units to which CSP-F is to be applied.3.2.12 sampling frequency, nf, desired ratio between thenumber of units of
29、 product randomly selected and inspected atan inspection station and the number of unit passing theinspection station during periods of sampling inspection.3.2.12.1 DiscussionIn this practice, each f is expressed asa fraction of the form, 1/7, 1/25, 1/50, etc. The procedure usedin selecting the samp
30、le units should give each unit of productpresented during periods of sampling inspection an equalchance of being selected and inspected. Also referred to as“frequency of sampling”.3.2.13 sampling inspection, ninspection for the defectsconcerned where the units selected for inspection are selectedby
31、sampling.3.2.14 screening, n100 % inspection where all defectiveunits are removed from the production flow.3.2.14.1 DiscussionThe two terms, screening and 100 %inspection, are used interchangeably in this practice.3.2.15 single-level, nplan consisting of alternating periodsof 100 % inspection and sa
32、mpling inspection wherein thesampling rate is constant.4. Significance and Use4.1 The reason for preserving military sampling standards isthat many organizations throughout the world still use thesestandards in their current form. MIL-STD-1235B is no longersupported by the U.S. Department of Defense
33、 as of themid-1990s and is out of print, but does exist in the publicdomain. This practice represents a conversion of MIL-STD-1235B to an ASTM-supported standard.4.2 This practice provides the tables and procedures forapplying five different types of continuous sampling plans forinspection by attrib
34、utes. These continuous sampling plans arediscussed in Sections 610of this practice and each sectionincludes information on:(a) Initiation of 100 % inspection in use.E2819 11 (2015)2(b) Requirements on when to switch to sampling inspec-tion.(c) Conditions warranting a return to 100 % inspection.(d) W
35、hen a change in Code Letter, if desired, can be made.(e) What to do when the checking inspector finds a defectthat was originally found conforming by the screeninginspector(s), that is, ineffective screening.(f) Situations where a defect is found before the switch to100 % inspection causing excessiv
36、e periods of 100 % inspec-tion so action must be taken, that is, long periods of screening.4.2.1 Section 6 (Section 2 in MIL-STD-1235B) describesspecific procedures and applications of the CSP-1 samplingplansa single-level continuous sampling procedure whichprovides for alternating between sequences
37、 of 100 % inspec-tion and sampling inspection.4.2.2 Section 7 (Section 3 in MIL-STD-1235B) describesspecific procedures and applications of the CSP-F samplingplansa variation of the CSP-1 plans in that CSP-F plans areapplied to a relatively short run of product, thereby permittingsmaller clearance n
38、umbers to be used.4.2.3 Section 8 (Section 4 in MIL-STD-1235B) describesspecific procedures and applications of the CSP-2 samplingplansa modification of CSP-1 in that 100 % inspectionresumes only after a prescribed number of defect-free unitsseparate any two defective sample units.4.2.4 Section 9 (S
39、ection 5 in MIL-STD-1235B) describesspecific procedures and applications of the CSP-T samplingplansa multi-level continuous sampling procedure whichprovides for reducing the sampling frequency upon demonstra-tion of superior product quality.4.2.5 Section 10 (Section 6 in MIL-STD-1235B) describesspec
40、ific procedures and applications of the CSP-V samplingplansa single-level continuous sampling procedure which isan alternative to CSP-T in that these plans provide for reducingthe clearance number in good quality situations where reduc-tion of sampling frequency has no economic merit.5. General Desc
41、ription of Sampling Plans5.1 This practice establishes continuous sampling plans andprocedures for inspection by attributes. When this practice isreferenced in a contract, specification, inspection standard orsimilar document, the provisions of this practice shall governthe application of all attrib
42、utes type continuous sampling plansand procedures. Unless otherwise noted herein, the provisionsof this practice shall be carried out by the supplier.5.2 ApplicationThe conditions that must exist beforethese sampling plans may be used are: (a) moving product, (b)ample space, equipment and manpower a
43、t or near the site ofinspection to permit rapid 100 % inspection when required, (c)relatively easy and quick inspection, (d) a process which isproducing, or is capable of producing, material whose qualityis stable, and (e) the inspection is non-destructive. The sam-pling plans designated herein are
44、applicable, but not limited, toinspection of various entities, viz., end items, components, rawmaterials, data or records, and any other entities, provided thatthe foregoing conditions are satisfied.5.3 Classification of Defects:5.3.1 Method of Classifying DefectsA classification ofdefects is the en
45、umeration of possible defects of the unit ofproduct classified according to their seriousness. Defects willnormally be grouped into one or more of the following classes;however, defects may be grouped into other classes, or intosubclasses within these classes.5.3.1.1 Critical DefectA critical defect
46、 is a defect thatjudgment and experience indicate is likely to result in hazard-ous or unsafe conditions for individuals using, maintaining, ordepending upon the product; or a defect that judgment andexperience indicate is likely to prevent performance of thetactical function of a major end item suc
47、h as a ship, aircraft,tank, missile, or space vehicle. Note that for a special provisionrelating to critical defects, see 5.8.2.5.3.1.2 Major DefectA major defect is a defect other thancritical that is likely to result in failure or materially reduce theusability of the unit of product for its inten
48、ded purpose.5.3.1.3 Minor DefectA minor defect is a defect that is notlikely to reduce materially the usability of the unit of productfor its intended purpose, or is a departure from establishedstandards having little bearing on the effective use or operationof the unit.5.3.2 Method of Classifying D
49、efectivesA defective is aunit of product which contains one or more defects. Defectiveswill usually be classified as follows:5.3.2.1 Critical DefectiveA critical defective contains oneor more critical defects and may also contain major and minor,or both, defects. Note that for a special provision relating tocritical defectives, see 5.7.2.5.3.2.2 Major DefectiveA major defective contains one ormore major defects, and may also contain minor defects, butcontains no critical defects.5.3.2.3 Minor DefectiveA minor defective contains
